412 APPEXDIX E. — PALiEOXTOLOGT. 



Orthis UMBRACULUM? 

 Plate III. Fig. 6. 



The specimen corresponds with one from the carboniferous rocks 

 of Kentucky and Tennessee, which is referred to this species. It 

 is however somewhat distorted by pressure, and other specimens 

 are necessary for a full determination. 



Loc. Missouri River, above Fort Leavenworth. 



ACEPHAI.A. 



Avicula? custa. 



Plate IV. Fig. lab. 



Shell obliquely ovoid ; hinge line much shorter than the width 

 of the shell; beaks prominent, and the upper part of the shell 

 gibbous ; surface marked by fine even stride. 



This shell occurs, with a few other fossils, in thinly laminated 

 gray sandstone, which, judging from the notes of observation, lies 

 below the limestone of Fort Laramie. 



Tellinomya protexsa. Hall, (n. sp.) 



Plate IV. Fig. 3. 



Shell elongate-oval ; beaks placed about one-third the width of 

 the shell from the anterior extremity, somewhat pointed; surface 

 marked by fine concentric striae and some stronger lines of growth. 



Loc. near Le Bonte, with the preceding species. 



Cypricardia occidextalis. 



Plate IV. Fig. 2. 



Shell rhomboid-ovate; anterior extremity rounded; posterior 

 obliquely truncate ; posterior slope with a distinct carina extend- 

 ing from the back to the posterior basal margin; beak near the 

 anterior extremity ; surface marked by concentric striae and some 

 more elevated ridges or lines of growth.- 



This species occurs in a gray argillaceous limestone, associated 

 w^ith Productus, Ohonetes, etc. 



Loc. from the Big Blue River. 



